The present invention relates to isoquinolinone derivatives, and their use as pharmaceuticals. In particular, the present invention relates to the use of these compounds to inhibit the activity of the enzyme poly (ADP-ribose)polymerase, also known as poly(ADP-ribose)synthase and poly ADP-ribosyltransferase, and commonly referred to as PARP.
The mammalian enzyme PARP (a 113-kDa multidomain protein) has been implicated in the signalling of DNA damage through its ability to recognize and rapidly bind to DNA single or double strand breaks (D""Amours et al, 1999, Biochem. J. 342: 249-268).
Several observations have led to the conclusion that PARP participates in a variety of DNA-related functions including gene amplification, cell division, differentiation, apoptosis, DNA base excision repair and also effects on telomere length and chromosome stability (d""Adda di Fagagna et al, 1999, Nature Gen., 23(1): 76-80).
Studies on the mechanism by which PARP modulates DNA repair and other processes has identified its importance in the formation of poly (ADP-ribose) chains within the cellular nucleus (Althaus, F. R. and Richter, C., 1987, ADP-Ribosylation of Proteins: Enzymology and Biological Significance, Springer-Verlag, Berlin). The DNA-bound, activated PARP utilizes NAD to synthesize poly (ADP-ribose) on a variety of nuclear target proteins, including topoisomerase, histones and PARP itself (Rhun et al, 1998, Biochem. Biophys. Res. Commun., 245: 1-10)
Poly (ADP-ribosyl)ation has also been associated with malignant transformation. For example, PARP activity is higher in the isolated nuclei of SV40-transformed fibroblasts, while both leukemic cells and colon cancer cells show higher enzyme activity than the equivalent normal leukocytes and colon mucosa (Miwa et al, 1977, Arch. Biochem. Biophys. 181: 313-321; Burzio et al, 1975, Proc. Soc. Exp. Bioi. Med. 149: 933-938; and Hirai et al, 1983, Cancer Res. 43: 3441-3446).
A number of low-molecular-weight inhibitors of PARP have been used to elucidate the functional role of poly (ADP-ribosyl)ation in DNA repair. In cells treated with alkylating agents, the inhibition of PARP leads to a marked increase in DNA-strand breakage and cell killing (Durkacz et al, 1980, Nature 283: 593-596; Berger, N. A., 1985, Radiation Research, 101: 4-14).
Subsequently, such inhibitors have been shown to enhance the effects of radiation response by suppressing the repair of potentially lethal damage (Ben-Hur et al, 1984, British Journal of Cancer, 49 (Suppl. VI): 34-42; Schlicker et al, 1999, Int. J. Radiat. Bioi., 75: 91-100). PARP inhibitors have been reported to be effective in radio sensitising hypoxic tumour cells (U.S. Pat. Nos. 5,032,617; 5,215,738 and 5,041,653).
Furthermore, PARP knockout (PARP xe2x88x92/xe2x88x92) animals exhibit genomic instability in response to alkylating agents and xcex3-irradiation (Wang et al, 1995, Genes Dev., 9: 509-520; Menissier de Murcia et al, 1997, Proc. Natl. Acad. Sci. USA, 94: 7303-7307).
A role for PARP has also been demonstrated in certain vascular diseases, septic shock, ischaemic injury and neurotoxicity (Cantoni et al, 1989, Biochim. Biophys. Acta, 1014: 1-7; Szabo, et al, 1997, J. Clin. Invest., 100: 723-735). Oxygen radical DNA damage that leads to strand breaks in DNA, which are subsequently recognised by PARP, is a major contributing factor to such disease states as shown by PARP inhibitor studies (Cosi et al, 1994, J. Neurosci. Res., 39: 38-46; Said et al, 1996, Proc. Natl. Acad. Sci. U.S.A., 93: 4688-4692). More recently, PARP has been demonstrated to play a role in the pathogenesis of haemorrhagic shock (Liaudet et al, 2000, Proc. Natl. Acad. Sci. U.S.A., 97(3): 10203-10208).
It has also been demonstrated that efficient retroviral infection of mammalian cells is blocked by the inhibition of PARP activity. Such inhibition of recombinant retroviral vector infections was shown to occur in various different cell types (Gaken et al, 1996, J. Virology, 70(6): 3992-4000). Inhibitors of PARP have thus been developed for the use in anti-viral therapies and in cancer treatment (WO91/18591)
Moreover, PARP inhibition has been speculated to delay the onset of aging characteristics in human fibroblasts (Rattan and Clark, 1994, Biochem. Biophys. Res. Comm., 201 (2): 665-672). This may be related to the role that PARP plays in controlling telomere function (d""Adda di Fagagna et al, 1999, Nature Gen., 23(1): 76-80).
EP 0 355 750 discloses classes of 5-substituted isoquinolinones and dihydroisoquinolinones as PARP inhibitors. Exemplified substituents on the nitrogen containing ring, at the 3 and/or 4 position, include methyl, phenyl, bromo or amino.
WO 99/11624 discloses a number of PARP inhibitors, amongst which are some isoquinolinone derivatives.
The present inventors have now discovered that further derivatives of isoquinolinone and dihydroisoquinolinone and related compounds act as PARP inhibitors.
Accordingly, the first aspect of the present invention provides a method of treatment of a disease of the human or animal body mediated by PARP comprising administering to such a subject a therapeutically effective amount of a compound of formula: 
and isomers, salts, solvates, chemically protected forms, and prodrugs thereof, wherein:
A and B together represent an optionally substituted, fused aromatic ring;
the dotted line between the 3 and 4 positions indicates the optional presence of a double bond;
at least one of RC1 and RC2 is independently represented by -L-RL, and if one of RC1 and RC2 is not represented by -L-RL, then that group is H, where L is of formula:
xe2x80x94(CH2)n1-Qn2-(CH2)n3xe2x80x94
wherein n1, n2 and n3 are each selected from 0, 1, 2 and 3, the sum of n1, n2 and n3 is 1, 2 or 3 and each Q (if n2 is greater than 1) is selected from O, S, NR3, C(xe2x95x90O), or -cR1R2xe2x80x94, where R1 and R2 are independently selected from hydrogen, halogen or optionally substituted C1-7 alkyl, or may together with the carbon atom to which they are attached form a C3-7 cyclic alkyl group, which may be saturated (a C3-7 cycloalkyl group) or unsaturated (a C3-7 cycloalkenyl group), or one of R1 and R2 may be attached to an atom in RL to form an unsaturated C3-7 cycloalkenyl group which comprises the carbon atoms to which R1 and R2 are attached in Q, xe2x80x94(CH2)n3xe2x80x94 (if present) and part of RL, and where R3 is selected from H or C1-7 alkyl; and
RL is selected from optionally substituted C3-20 heterocyclyl, C5-20 aryl and carbonyl; and
RN is selected from hydrogen, optionally substituted C1-7 alkyl, C3-20 heterocyclyl, C5-20 aryl, hydroxy, ether, nitro, amino, thioether, sulfoxide and sulfone.
A second aspect of the present invention relates to a compound of the formula: 
or an isomer, salt, solvate, chemically protected form, and prodrug thereof, wherein:
A and B together represent an optionally substituted, fused aromatic ring;
the dotted line between the 3 and 4 positions indicates the optional presence of a double bond;
one of RC1 and RC2 is xe2x80x94CH2xe2x80x94RL, and the other of RC1 and RC2 is H;
RL is optionally substituted phenyl; and
RN is hydrogen.
A third aspect of the present invention relates to a pharmaceutical composition comprising a compound of the second aspect and a pharmaceutically acceptable carrier or diluent.
Further aspects of the invention provide for a method of treatment as described in the first aspect of the invention, wherein the disease mediated by PARP is: vascular disease; septic shock; ischaemic injury; neurotoxicity; haemorraghic shock; or viral infection.
A further aspect of the invention provides a method of cancer therapy for the human or animal body comprising administering to such a subject a therapeutically effective amount of a compound as described in the first aspect in combination with chemotherapy or radiation therapy.
Another further aspect of the invention provides a method of potentiating tumour cells for treatment with ionising radiation or chemotherapeutic agents comprising administering to said cells a compound as described in the first aspect of the invention. such a method may be practised in vivo or in vitro.
It is preferred that when a compound is administered it is done so in the form of a pharmaceutical composition.
Definitions
The term xe2x80x9caromatic ringxe2x80x9d is used herein in the conventional sense to refer to a cyclic aromatic structure, that is, a cyclic structure having delocalised xcfx80-electron orbitals.
The aromatic ring fused to the main core, i.e. that formed by -A-B-, may bear further fused aromatic rings (resulting in, e.g. naphthyl or anthracenyl groups). The aromatic ring(s) may comprise solely carbon atoms, or may comprise carbon atoms and one or more heteroatoms, including but not limited to, nitrogen, oxygen, and sulfur atoms. The aromatic ring(s) preferably have five or six ring atoms.
The aromatic ring(s) may optionally be substituted. If a substituent itself comprises an aryl group, this aryl group is not considered to be a part of the aryl group to which it is attached. For example, the group biphenyl is considered herein to be a phenyl group (an aryl group comprising a single aromatic ring) substituted with a phenyl group. Similarly, the group benzylphenyl is considered to be a phenyl group (an aryl group comprising a single aromatic ring) substituted with a benzyl group.
In one group of preferred embodiments, the aromatic group comprises a single aromatic ring, which has five or six ring atoms, which ring atoms are selected from carbon, nitrogen, oxygen, and sulfur, and which ring is optionally substituted. Examples of these groups include benzene, pyrazine, pyrrole, thiazole, isoxazole, and oxazole. 2-Pyrone can also be considered to be an aromatic ring, but is less preferred.
If the aromatic ring has six atoms, then preferably at least four, or even five or all, of the ring atoms are carbon. The other ring atoms are selected from nitrogen, oxygen and sulphur, with nitrogen and oxygen being preferred. Suitable groups include a ring with: no hetero atoms (benzene); one nitrogen ring atom (pyridine); two nitrogen ring atoms (pyrazine, pyrimidine and pyridazine); one oxygen ring atom (pyrone); and one oxygen and one nitrogen ring atom (oxazine).
If the aromatic ring has five ring atoms, then preferably at least three of the ring atoms are carbon. The remaining ring atoms are selected from nitrogen, oxygen and sulphur. Suitable rings include a ring with: one nitrogen ring atom (pyrrole); two nitrogen ring atoms (imidazole, pyrazole); one oxygen ring atom (furan); one sulphur ring atom (thiophene); one nitrogen and one sulphur ring atom (isothiazole or thiazole); and one nitrogen and one oxygen ring atom (isoxazole or oxazole).
The aromatic ring may bear one or more substituent groups at any available ring position. These substituents are selected from halo, nitro, hydroxy, ether, thiol, thioether, amino, C1-7 alkyl, C3-20 heterocyclyl and C5-20 aryl. The aromatic ring may also bear one or more substituent groups which together form a ring. In particular these may be of formula xe2x80x94(CH2)mxe2x80x94 or xe2x80x94Oxe2x80x94(CH2)pxe2x80x94Oxe2x80x94, where m is 2, 3, 4 or 5 and p is 1, 2 or 3.
C1-7 alkyl: The term xe2x80x9cC1-7 alkylxe2x80x9d as used herein, pertains to a monovalent moiety obtained by removing a hydrogen atom from a C1-7 hydrocarbon compound having from 1 to 7 carbon atoms, which may be aliphatic or alicyclic, or a combination thereof, and which may be saturated, partially unsaturated, or fully unsaturated.
Examples of (unsubstituted) saturated linear C1-7 alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, n-butyl, and n-pentyl (amyl).
Examples of (unsubstituted) saturated branched C1-7 alkyl groups include, but are not limited to, iso-propyl, iso-butyl, sec-butyl, tert-butyl, and neo-pentyl.
Examples of saturated alicyclic (carbocyclic) C1-7 alkyl groups (also referred to as xe2x80x9cC3-7 cycloalkylxe2x80x9d groups) include, but are not limited to, unsubstituted groups such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl, as well as substituted groups (e.g. groups which comprise such groups), such as methylcyclopropyl, dimethylcyclopropyl, methylcyclobutyl, dimethylcyclobutyl, methylcyclopentyl, dimethylcyclopentyl, methylcyclohexyl, cyclopropylmethyl and cyclohexylmethyl.
Examples of (unsubstituted) unsaturated C1-7 alkyl groups which have one or more carbonxe2x80x94carbon double bonds (also referred to as xe2x80x9cC2-7 alkenylxe2x80x9d groups) include, but are not limited to, ethenyl (vinyl, xe2x80x94CHxe2x95x90CH2), 2-propenyl (allyl, xe2x80x94CH2xe2x80x94CHxe2x95x90CH2), isopropenyl (xe2x80x94C(CH3)xe2x95x90CH2), butenyl, pentenyl, and hexenyl.
Examples of (unsubstituted) unsaturated C1-7 alkyl groups which have one or more carbonxe2x80x94carbon triple bonds (also referred to as xe2x80x9cC2-7 alkynylxe2x80x9d groups) include, but are not limited to, ethynyl (ethinyl) and 2-propynyl (propargyl).
Examples of unsaturated alicyclic (carbocyclic) C1-7 alkyl groups which have one or more carbonxe2x80x94carbon double bonds (also referred to as xe2x80x9cC3-7 cycloalkenylxe2x80x9d groups) include, but are not limited to, unsubstituted groups such as cyclopropenyl, cyclobutenyl, cyclopentenyl, and cyclohexenyl, as well as substituted groups (e.g. groups which comprise such groups) such as cyclopropenylmethyl and cyclohexenylmethyl.
C3-20 heterocyclyl: The term xe2x80x9cC3-20 heterocyclyl,xe2x80x9d as used herein, pertains to a monovalent moiety obtained by removing a hydrogen atom from a ring atom of a non-aromatic C3-20 heterocyclic compound, said compound having one ring, or two or more rings (e.g. spiro, fused, bridged), and having from 3 to 20 ring atoms, of which from 1 to 10 are ring heteroatoms, and wherein at least one of said ring(s) is a heterocyclic ring. Preferably, each ring has from 3 to 7 ring atoms, of which from 1 to 4 are ring heteroatoms. xe2x80x9cC3-20xe2x80x9d denotes ring atoms, whether carbon atoms or heteroatoms.
Examples of C3-20 heterocyclyl groups having one nitrogen ring atom include, but are not limited to, those derived from aziridine, azetidine, azetine, pyrrolidine, pyrroline, piperidine, dihydropyridine, tetrahydropyridine, and dihydropyrrole (azoline).
Examples of C3-20 heterocyclyl groups having one oxygen ring atom include, but are not limited to, those derived from oxirane, oxetane, oxolane (tetrahydrofuran), oxole (dihydrofuran), oxane (tetrahydropyran), dihydropyran, and pyran. Examples of substituted C3-20 heterocyclyl groups include sugars, in cyclic form, for example, furanoses and pyranoses, including, for example, ribose, lyxose, xylose, galactose, sucrose, fructose, and arabinose.
Examples of C3-20 heterocyclyl groups having one sulfur ring atom include, but are not limited to, those derived from thiolane (tetrahydrothiophene, thiane) and tetrahydrothiopyran.
Examples of C3-20 heterocyclyl groups having two oxygen ring atoms include, but are not limited to, those derived from dioxane, for example 1,3-dioxane and 1,4-dioxane.
Examples of C3-20 heterocyclyl groups having two nitrogen ring atoms include, but are not limited to, those derived from diazolidine (pyrazolidine), pyrazoline, imidazolidine, imidazoline, and piperazine.
Examples of C3-20 heterocyclyl groups having one nitrogen ring atom and one oxygen ring atom include, but are not limited to, those derived from tetrahydrooxazole, dihydrooxazole, tetrahydroisoxazole, dihydroiosoxazole, morpholine, tetrahydrooxazine, dihydrooxazine, and oxazine.
Examples of C3-20 heterocyclyl groups having one oxygen ring atom and one sulfur ring atom include, but are not limited to, those derived from oxathiolane and oxathiane.
Examples of C3-20 heterocyclyl groups having one nitrogen ring atom and one sulfur ring atom include, but are not limited to, those derived from thiazoline, thiazolidine, and thiomorpholine.
Other examples of C3-20 heterocyclyl groups include, but are not limited to, oxadiazine.
If the C3-20 heterocyclyl is substituted, the substituents are on carbon, or nitrogen (if present), atoms.
C5-20 aryl: The term xe2x80x9cC5-20 aryl,xe2x80x9d as used herein, pertains to a monovalent moiety obtained by removing a hydrogen atom from an aromatic ring atom of a C5-20 aromatic compound, said compound having one ring, or two or more rings (e.g. fused), and having from 5 to 20 ring atoms, and wherein at least one of said ring(s) is an aromatic ring. Preferably, each ring has from 5 to 7 ring atoms.
The ring atoms may be all carbon atoms, as in xe2x80x9ccarboaryl groups,xe2x80x9d in which case the group may conveniently be referred to as a xe2x80x9cC5-20 carboarylxe2x80x9d group.
Examples of C5-20 aryl groups which do not have ring heteroatoms (i.e., C5-20 carboaryl groups) include, but are not limited to, those derived from benzene (i.e., phenyl) (C6), naphthalene (C10), anthracene (C14), phenanthrene (C14), and pyrene (C16).
Alternatively, the ring atoms may include one or more heteroatoms, including but not limited to oxygen, nitrogen, and sulfur, as in xe2x80x9cheteroaryl groups.xe2x80x9d In this case, the group may conveniently be referred to as a xe2x80x9cC5-20 heteroarylxe2x80x9d group, wherein xe2x80x9cC5-20xe2x80x9d denotes ring atoms, whether carbon atoms or heteroatoms. Preferably, each ring has from 5 to 7 ring atoms, of which from 0 to 4 are ring heteroatoms.
Examples of C5-20 heteroaryl groups include, but are not limited to, C5 heteroaryl groups derived from furan (oxole), thiophene (thiole), pyrrole (azole), imidazole (1,3-diazole), pyrazole (1,2-diazole), triazole, oxazole, isoxazole, thiazole, isothiazole, oxadiazole, oxatriazole, and tetrazole; and C6 heteroaryl groups derived from isoxazine, pyridine (azine), pyridazine (1,2-diazine), pyrimidine (1,3-diazine; e.g. cytosine, thymine, uracil), pyrazine (1,4-diazine), and triazine.
The heteroaryl group may be bonded via a carbon or hetero ring atom.
Examples of C5-20 heteroaryl groups which comprise fused rings, include, but are not limited to, C9 heteroaryl groups derived from benzofuran, isobenzofuran, benzothiophene, indole, isoindole; C10 heteroaryl groups derived from quinoline, isoquinoline, benzodiazine, pyridopyridine; C14 heteroaryl groups derived from acridine and xanthene.
The above C1-7 alkyl, C3-20 heterocyclyl, and C5-20 aryl groups, whether alone or part of another substituent, may themselves optionally be substituted with one or more groups selected from themselves and the additional substituents listed below
Halo: xe2x80x94F, xe2x80x94Cl, xe2x80x94Br, and xe2x80x94I.
Hydroxy: xe2x80x94OH.
Ether: xe2x80x94OR, wherein R is an ether substituent, for example, a C1-7 alkyl group (also referred to as a C1-7alkoxy group), a C3-20 heterocyclyl group (also referred to as a C3-20 heterocyclyloxy group), or a C5-20 aryl group (also referred to as a C5-20 aryloxy group), preferably a C1-7 alkyl group.
Nitro: xe2x80x94NO2.
Cyano (nitrile, carbonitrile): xe2x80x94CN.
Carbonyl: a group of structure xe2x80x94C(xe2x95x90O)xe2x80x94, which includes acyl, carboxy, ester and amido.
Acyl (keto): xe2x80x94C(xe2x95x90O)R, wherein R is an acyl substituent, for example, a C1-7 alkyl group (also referred to as C1-7 alkylacyl or C1-7 alkanoyl), a C3-20 heterocyclyl group (also referred to as C3-20 heterocyclylacyl), or a C5-20 aryl group (also referred to as C5-20 arylacyl), preferably a C1-7 alkyl group. Examples of acyl groups include, but are not limited to, xe2x80x94C(xe2x95x90O)CH3 (acetyl), xe2x80x94C(xe2x95x90O)CH2CH3 (propionyl) xe2x80x94C(xe2x95x90O)C(CH3)3 (pivaloyl), and xe2x80x94C(xe2x95x90O)Ph (benzoyl, phenone).
Carboxy (carboxylic acid): xe2x80x94COOH.
Ester (carboxylate, carboxylic acid ester, oxycarbonyl): xe2x80x94C(xe2x95x90O)OR, wherein R is an ester substituent, for example, a C1-7 alkyl group, a C3-20 heterocyclyl group, or a C5-20 aryl group, preferably a C1-7 alkyl group. Examples of ester groups include, but are not limited to, xe2x80x94C(xe2x95x90O)OCH3, xe2x80x94C(xe2x95x90O)OCH2CH3, xe2x80x94C(xe2x95x90O)OC(CH3)3, and xe2x80x94C(xe2x95x90O)OPh.
Amido (carbamoyl, carbamyl, aminocarbonyl, carboxamide): xe2x80x94C(xe2x95x90O)NR1R2, wherein R1 and R2 are independently amino substituents, as defined for amino groups. Examples of amido groups include, but are not limited to, xe2x80x94C(xe2x95x90O)NH2, xe2x80x94C(xe2x95x90O)NHCH3, xe2x80x94C(xe2x95x90O)N(CH3)2, xe2x80x94C(xe2x95x90O)NHCH2CH3, and xe2x80x94C(xe2x95x90O)N(CH2CH3)2, as well as amido groups in which R1 and R2, together with the nitrogen atom to which they are attached, form a heterocyclic structure as in, for example, piperidinocarbonyl, morpholinocarbonyl, thiomorpholinocarbonyl, and piperazinocarbonyl.
Amino: xe2x80x94NR1R2, wherein R1 and R2 are independently amino substituents, for example, hydrogen, a C1-7 alkyl group (also referred to as C1-7 alkylamino or di-C1-7 alkylamino), a C3-20 heterocyclyl group, or a C5-20 aryl group, preferably H or a C1-7 alkyl group, or, in the case of a xe2x80x9ccyclicxe2x80x9d amino group, R1 and R2, taken together with the nitrogen atom to which they are attached, form a heterocyclic ring having from 4 to 8 ring atoms. Examples of amino groups include, but are not limited to, xe2x80x94NH2, xe2x80x94NHCH3, xe2x80x94NHCH(CH3)2, xe2x80x94N(CH3)2, xe2x80x94N(CH2CH3)2, and xe2x80x94NHPh. Examples of cyclic amino groups include, but are not limited to, aziridino, azetidino, pyrrolidino, piperidino, piperazino, perhydrodiazepino, morpholino, and thiomorpholino. The cyclic amino groups may be substituted on their ring by any of the substituents defined here, for example carboxy, carboxylate and amido. A particular form of amino group is where one of R1 and R2 is a sulfone (xe2x80x94S(xe2x95x90O)2R), where R is a sulfone substituent, and this group can be termed a sulfonamido group. Examples of sulfonamido groups include, but are not limited to, xe2x80x94NHS(xe2x95x90O)2CH3, xe2x80x94NHS(xe2x95x90O)2Ph and xe2x80x94NHS(xe2x95x90O)2C6H4F.
Acylamido (acylamino): xe2x80x94NR1C(xe2x95x90O)R2, wherein R1 is an amide substituent, for example, hydrogen, a C1-7 alkyl group, a C3-20 heterocyclyl group, or a C5-20 aryl group, preferably H or a C1-7alkyl group, most preferably H, and R2 is an acyl substituent, for example, a C1-7 alkyl group, a C3-20 heterocyclyl group, or a C5-20 aryl group, preferably a C1-7 alkyl group. Examples of acylamido groups include, but are not limited to, xe2x80x94NHC(xe2x95x90O)CH3, xe2x80x94NHC(xe2x95x90O)CH2CH3, and xe2x80x94NHC(xe2x95x90O)Ph. One particular form of acylamido group is where R2 is an amino group (xe2x80x94NR3R4), where R3 and R4 are independently amino substituents, and this group can be termed an ureido group. Examples of ureido groups include, but are not limited to xe2x80x94NHC(xe2x95x90O)NHCH3, xe2x80x94NHC(xe2x95x90O)NHCH2CH3, and xe2x80x94NHC(xe2x95x90O)NHPh.
Acyloxy (reverse ester): xe2x80x94OC(xe2x95x90O)R, wherein R is an acyloxy substituent, for example, a C1-7 alkyl group, a C3-20 heterocyclyl group, or a C5-20 aryl group, preferably a C1-7 alkyl group. Example of acyloxy groups include, but are not limited to, xe2x80x94OC(xe2x95x90O)CH3 (acetoxy), xe2x80x94OC(xe2x95x90O)CH2CH3, xe2x80x94OC(xe2x95x90O)C(CH3)3, xe2x80x94OC(xe2x95x90O)Ph, xe2x80x94OC(xe2x95x90O)CH4F, and xe2x80x94OC(xe2x95x90O)CH2Ph.
Thiol: xe2x80x94SH.
Thioether (sulfide): xe2x80x94SR, wherein R is a thioether substituent, for example, a C1-7 alkyl group (also referred to as a C1-7 alkylthio group), a C3-20 heterocyclyl group, or a C5-20 aryl group, preferably a C1-7 alkyl group. Examples of C1-7 alkylthio groups include, but are not limited to, xe2x80x94SCH3 and xe2x80x94SCH2CH3.
Sulfoxide (sulfinyl): xe2x80x94S(xe2x95x90O)R, wherein R is a sulfoxide substituent, for example, a C1-7 alkyl group, a C3-20 heterocyclyl group, or a C5-20 aryl group, preferably a C1-7 alkyl group. Examples of sulfoxide groups include, but are not limited to, xe2x80x94S(xe2x95x90O)CH3 and xe2x80x94S(xe2x95x90O)CH2CH3.
Sulfone (sulfonyl): xe2x80x94S(xe2x95x90O)2R, wherein R is a sulfone substituent, for example, a C1-7 alkyl group, a C3-20 heterocyclyl group, or a C5-20 aryl group, preferably a C1-7 alkyl group. Examples of sulfone groups include, but are not limited to, xe2x80x94S(xe2x95x90O)2CH3 (methanesulfonyl, mesyl), xe2x80x94S(xe2x95x90O)2CF3, xe2x80x94S(xe2x95x90O)2CH2CH3, and 4-methylphenylsulfonyl (tosyl).
As mentioned above, the groups that form the above listed substituent groups, e.g. C1-7 alkyl, C3-20 heterocyclyl and C5-20 aryl, may themselves be substituted. Thus, the above definitions cover substituent groups which are substituted.
Substituents Form a Ring
It is possible that a substituent on a ring which forms part of RC1 and a substituent on the fused aromatic ring (represented by -A-B-), may together form an intra ring link, thus forming a further cyclic structure in the compound.
The substituent on the aromatic ring that forms the intra ring link is preferably on the atom adjacent the central moiety (i.e. at the xcex1-position).
The substituent on RC1 that forms the intra ring link is preferably on the atom which is one atom away from the atom which is bound to the central moiety.
The link between the two rings may be a single bond, or may be of the formula:
xe2x80x94(CH2)n1xe2x80x2-Qxe2x80x2n2xe2x80x2-(CH2)n3xe2x80x2xe2x80x94
wherein n1xe2x80x2, n2xe2x80x2 and n3xe2x80x2 are each selected from 0, 1, 2 and 3 and the sum of n1xe2x80x2, n2xe2x80x2 and n3xe2x80x2 is less than or equal to 3. Each Qxe2x80x2 (if n2xe2x80x2 is greater than 1) is selected from O, S, NRxe2x80x23, C(xe2x95x90O), or xe2x80x94CRxe2x80x21Rxe2x80x22xe2x80x94, where Rxe2x80x21 and Rxe2x80x22 are independently selected from hydrogen, halogen or optionally substituted C1-7 alkyl, or may together with the carbon atom to which they are attached form a C3-7 cyclic alkyl group, which may be saturated (a C3-7 cycloalkyl group) or unsaturated (a C3-7 cycloalkenyl group), and where Rxe2x80x23 is selected from H or C1-7 alkyl.
Further Preferences
It is preferred that there is a double bond present between the third and fourth positions of the compound.
It is also preferred that only one of RC1 and RC2 is represented by -L-RL, and the other of RC1 and RC2 is H. The preferences for L and RL expressed below may be different for RC1 and RC2.
The fused aromatic ring(s) represented by -A-B- preferably consist of solely carbon ring atoms, and thus may be benzene, naphthalene, and is more preferably benzene. As described above, these rings may be substituted, but in some embodiments are preferably unsubstituted.
RN is preferably selected from hydrogen, and C1-7 alkyl, which may be substituted or unsubstituted. In one embodiment, RN is preferably C1-3 alkyl, which may be substituted, for example by a C5-20 heterocyclic group. Suitable such groups include cyclic amino groups such as piperidino or morpholino. In another embodiment, RN is preferably H.
In L, it is preferred that each Q (if n2 is greater than 1) is selected from O, S, NH or C(xe2x95x90O).
L is preferably of formula:
xe2x80x94(CH2)n1-Qn2-, where n1 is selected from 0, 1, 2 and 3 and n2 is selected from 0 and 1 (where the sum of n1 and n2 is 1, 2 or 3), and more preferably n1 is 1 or 2. The more preferred options for L are xe2x80x94CH2xe2x80x94 or xe2x80x94C2H4xe2x80x94, with xe2x80x94C2H4xe2x80x94 being the most preferred for RC2 and xe2x80x94CH2xe2x80x94 being the most preferred for RC1.
If Q in L is xe2x80x94CR1R2xe2x80x94, then n2 is preferably 1. In one embodiment, R1 is optionally substituted C1-7 alkyl and R2 is hydrogen. R1 is more preferably optionally substituted C1-4 alkyl, and most preferably unsubstituted C1-4 alkyl. In another embodiment, R1 and R2, together with the carbon atom to which they are attached, form a saturated C3-7 cyclic alkyl group, more preferably a C5-7 cyclic alkyl group. In a further embodiment, R1 is attached to an atom in RL to form an unsaturated C3-7 cycloalkenyl group, more preferably a C5-7 cycloalkenyl group, which comprises the carbon atoms to which R1 and R2 are attached in Q, xe2x80x94(CH2)n3xe2x80x94 (if present) and part of RL, and R2 is hydrogen.
RL is preferably C5-20 aryl, and more preferably a benzene ring, naphthalene, pyridine, 1,3-benzodioxole or furan.
When RL is a benzene ring, it is preferably substituted. The one or more substituents may be selected from: C1-7 alkyl, more preferably methyl, CF3; C5-20 aryl; C3-20 heterocyclyl; halo, more preferably fluoro; hydroxy; ether, more preferably methoxy, phenoxy, benzyloxy, and cyclopentoxy; nitro; cyano; carbonyl groups, such as carboxy, ester and amido; amino (including sulfonamido), more preferably xe2x80x94NH2, xe2x80x94NHPh, and cycloamino groups, such as morpholino; acylamido, including ureido groups, where the acyl or amino substituent is preferably phenyl, which itself is optionally fluorinated; acyloxy; thiol; thioether; sulfoxide; sulfone.
In one group of embodiments, fluoro is particularly preferred as a substituent, along with substituents containing a phenyl, or fluorinated phenyl, component.
Preferred substituents of the benzene ring, when RL is phenyl, include:
(i) acylamido, wherein the amide substituent is selected from C1-7 alkyl, C3-20 heterocyclyl, and C5-20 aryl, more preferably C1-7 alkyl and C5-20 aryl, which groups are optionally further substituted. The optional substituents may be selected from any of those listed above, but those of particular interest include C1-7 alkyl and C5-20 aryl groups, halo, ether, thioether and sulfone groups;
(ii) ureido, where one amine substituent is preferably hydrogen, and the other is selected from C1-7 alkyl, C3-20 heterocyclyl, and C5-20 aryl, more preferably C1-7 alkyl and C5-20 aryl, which groups are optionally further substituted. The optional substituents may be selected from any one of those listed above, but those of particular interest include C1-7 alkyl, C3-20 heterocyclyl and C5-20 aryl groups, halo and ether groups;
(iii) sulfonamino, wherein the amine substituent is preferably hydrogen and the sulfone substituent is selected from C1-7 alkyl, C3-20 heterocyclyl, and C5-20 aryl, more preferably C1-7 alkyl and C5-20 aryl, which groups are optionally further substituted. The optional substituents may be selected from any of those listed above, but those of particular interest include C5-20 aryl groups and acylamido groups;
(iv) acyloxy, wherein the acyloxy substituent is selected from C1-7 alkyl, C3-20 heterocyclyl, and C5-20 aryl, more preferably C1-7 alkyl and C5-20 aryl, which groups are optionally further substituted. The optional substituents may be selected from any of those listed above, but those of particular interest include C1-7 alkyl and C5-20 aryl groups, halo, ether, thioether, sulfone and nitro groups.
If A and B together represent a substituted fused aromatic ring, it is preferred that the substituent does not form an intra ring link with a substituent on a ring which forms part of Rc. Substituents in the five position are particularly preferred.
In particular, when RL is xe2x80x94CH2-phenyl, the phenyl group is preferably substituted.
Where appropriate, the above preferences may be taken in combination with each other.
Preferred Compounds
The following compounds are preferred embodiments of the first aspect of the invention: 
Includes Other Forms
Included in the above are the well known ionic, salt, solvate, and protected forms of these substituents. For example, a reference to carboxylic acid (xe2x80x94COOH) also includes the anionic (carboxylate) form (xe2x80x94COOxe2x88x92), a salt or solvate thereof, as well as conventional protected forms. Similarly, a reference to an amino group includes the protonated form (xe2x80x94N+HR1R2), a salt or solvate of the amino group, for example, a hydrochloride salt, as well as conventional protected forms of an amino group. Similarly, a reference to a hydroxyl group also includes the anionic form (xe2x80x94Oxe2x88x92), a salt or solvate thereof, as well as conventional protected forms of a hydroxyl group.
Isomers, Salts, Solvates, Protected Forms, and Prodrugs
Certain compounds may exist in one or more particular geometric, optical, enantiomeric, diasteriomeric, epimeric, stereoisomeric, tautomeric, conformational, or anomeric forms, including but not limited to, cis- and trans-forms; E- and Z-forms; c-, t-, and r-forms; endo- and exo-forms; R-, S-, and meso-forms; D- and L-forms; d- and l-forms; (+) and (xe2x88x92) forms; keto-, enol-, and enolate-forms; syn- and anti-forms; synclinal- and anticlinal-forms; xcex1- and xcex2-forms; axial and equatorial forms; boat-, chair-, twist-, envelope- and halfchair-forms; and combinations thereof, hereinafter collectively referred to as xe2x80x9cisomersxe2x80x9d (or xe2x80x9cisomeric formsxe2x80x9d).
If the compound is in crystalline form, it may exist in a number of different polymorphic forms.
Note that, except as discussed below for tautomeric forms, specifically excluded from the term xe2x80x9cisomers,xe2x80x9d as used herein, are structural (or constitutional) isomers (i.e. isomers which differ in the connections between atoms rather than merely by the position of atoms in space). For example, a reference to a methoxy group, xe2x80x94OCH3, is not to be construed as a reference to its structural isomer, a hydroxymethyl group, xe2x80x94CH2OH. Similarly, a reference to ortho-chlorophenyl is not to be construed as a reference to its structural isomer, meta-chlorophenyl. However, a reference to a class of structures may well include structurally isomeric forms falling within that class (e.g. C1-7alkyl includes n-propyl and iso-propyl; butyl includes n-, iso-, sec-, and tert-butyl; methoxyphenyl includes ortho-, meta-, and para-methoxyphenyl).
The above exclusion does not pertain to tautomeric forms, for example, keto-, enol-, and enolate-forms, as in, for example, the following tautomeric pairs: keto/enol, imine/enamine, amide/imino alcohol, amidine/amidine, nitroso/oxime, thioketone/enethiol, N-nitroso/hyroxyazo, and nitro/aci-nitro.
Particularly relevant to the present invention is the tautomeric pair that exists when RN is H, illustrated below: 
Note that specifically included in the term xe2x80x9cisomerxe2x80x9d are compounds with one or more isotopic substitutions. For example, H may be in any isotopic form, including 1H, 2H (D), and 3H (T); C may be in any isotopic form, including 12C, 3C, and 14C; O may be in any isotopic form, including 16O and 18O; and the like.
Unless otherwise specified, a reference to a particular compound includes all such isomeric forms, including (wholly or partially) racemic and other mixtures thereof. Methods for the preparation (e.g. asymmetric synthesis) and separation (e.g. fractional crystallisation and chromatographic means) of such isomeric forms are either known in the art or are readily obtained by adapting the methods taught herein, or known methods, in a known manner.
Unless otherwise specified, a reference to a particular compound also includes ionic, salt, solvate, and protected forms of thereof, for example, as discussed below.
It may be convenient or desirable to prepare, purify, and/or handle a corresponding salt of the active compound, for example, a pharmaceutically-acceptable salt. Examples of pharmaceutically acceptable salts are discussed in Berge et al., 1977, xe2x80x9cPharmaceutically Acceptable Salts,xe2x80x9d J. Pharm. Sci., Vol. 66, pp. 1-19.
For example, if the compound is anionic, or has a functional group which may be anionic (e.g. xe2x80x94COOH may be xe2x80x94COOxe2x88x92), then a salt may be formed with a suitable cation. Examples of suitable inorganic cations include, but are not limited to, alkali metal ions such as Na+ and K+, alkaline earth cations such as Ca2+ and Mg2+, and other cations such as Al+3. Examples of suitable organic cations include, but are not limited to, ammonium ion (i.e., NH4+) and substituted ammonium ions (e.g. NH3R+, NH2R2+, NHR3+, NR4+). Examples of some suitable substituted ammonium ions are those derived from: ethylamine, diethylamine, dicyclohexylamine, triethylamine, butylamine, ethylenediamine, ethanolamine, diethanolamine, piperazine, benzylamine, phenylbenzylamine, choline, meglumine, and tromethamine, as well as amino acids, such as lysine and arginine. An example of a common quaternary ammonium ion is N(CH3)4+.
If the compound is cationic, or has a functional group which may be cationic (e.g. xe2x80x94NH2 may be xe2x80x94NH3+), then a salt may be formed with a suitable anion. Examples of suitable inorganic anions include, but are not limited to, those derived from the following inorganic acids: hydrochloric, hydrobromic, hydroiodic, sulfuric, sulfurous, nitric, nitrous, phosphoric, and phosphorous. Examples of suitable organic anions include, but are not limited to, those derived from the following organic acids: acetic, propionic, succinic, gycolic, stearic, palmitic, lactic, malic, pamoic, tartaric, citric, gluconic, ascorbic, maleic, hydroxymaleic, phenylacetic, glutamic, aspartic, benzoic, cinnamic, pyruvic, salicyclic, sulfanilic, 2-acetyoxybenzoic, fumaric, toluenesulfonic, methanesulfonic, ethanesulfonic, ethane disulfonic, oxalic, isethionic, valeric, and gluconic. Examples of suitable polymeric anions include, but are not limited to, those derived from the following polymeric acids: tannic acid, carboxymethyl cellulose.
It may be convenient or desirable to prepare, purify, and/or handle a corresponding solvate of the active compound. The term xe2x80x9csolvatexe2x80x9d is used herein in the conventional sense to refer to a complex of solute (e.g. active compound, salt of active compound) and solvent. If the solvent is water, the solvate may be conveniently referred to as a hydrate, for example, a mono-hydrate, a di-hydrate, a tri-hydrate, etc.
It may be convenient or desirable to prepare, purify, and/or handle the active compound in a chemically protected form. The term xe2x80x9cchemically protected form,xe2x80x9d as used herein, pertains to a compound in which one or more reactive functional groups are protected from undesirable chemical reactions, that is, are in the form of a protected or protecting group (also known as a masked or masking group or a blocked or blocking group). By protecting a reactive functional group, reactions involving other unprotected reactive functional groups can be performed, without affecting the protected group; the protecting group may be removed, usually in a subsequent step, without substantially affecting the remainder of the molecule. See, for example, Protective Groups in Organic Synthesis (T. Green and P. Wuts, Wiley, 1991).
For example, a hydroxy group may be protected as an ether (xe2x80x94OR) or an ester (xe2x80x94OC(xe2x95x90O)R), for example, as: a t-butyl ether; a benzyl, benzhydryl (diphenylmethyl), or trityl (triphenylmethyl) ether; a trimethylsilyl or t-butyldimethylsilyl ether; or an acetyl ester (xe2x80x94OC(xe2x95x90O)CH3, xe2x80x94OAc).
For example, an aldehyde or ketone group may be protected as an acetal or ketal, respectively, in which the carbonyl group ( greater than Cxe2x95x90O) is converted to a diether ( greater than C(OR)2), by reaction with, for example, a primary alcohol. The aldehyde or ketone group is readily regenerated by hydrolysis using a large excess of water in the presence of acid.
For example, an amine group may be protected, for example, as an amide or a urethane, for example, as: a methyl amide (xe2x80x94NHCOxe2x80x94CH3); a benzyloxy amide (xe2x80x94NHCOxe2x80x94OCH2C6H5, xe2x80x94NH-Cbz); as a t-butoxy amide (xe2x80x94NHCOxe2x80x94OC(CH3)3, xe2x80x94NH-Boc); a 2-biphenyl-2-propoxy amide (xe2x80x94NHCOxe2x80x94OC(CH3)2C6H4C6H5, xe2x80x94NH-Bpoc), as a 9-fluorenylmethoxy amide (xe2x80x94NH-Fmoc), as a 6-nitroveratryloxy amide (xe2x80x94NH-Nvoc), as a 2-trimethylsilylethyloxy amide (xe2x80x94NH-Teoc), as a 2,2,2-trichloroethyloxy amide (xe2x80x94NH-Troc), as an allyloxy amide (xe2x80x94NH-Alloc), as a 2(-phenylsulphonyl)ethyloxy amide (xe2x80x94NH-Psec); or, in suitable cases, as an N-oxide ( greater than NOxe2x80xa2).
For example, a carboxylic acid group may be protected as an ester for example, as: an C1-7 alkyl ester (e.g. a methyl ester; a t-butyl ester); a C1-7 haloalkyl ester (e.g. a C1-7 trihaloalkyl ester); a triC1-7alkylsilyl-C1-7alkyl ester; or a C5-20 aryl-C1-7 alkyl ester (e.g. a benzyl ester; a nitrobenzyl ester); or as an amide, for example, as a methyl amide.
For example, a thiol group may be protected as a thioether (xe2x80x94SR), for example, as: a benzyl thioether; an acetamidomethyl ether (xe2x80x94Sxe2x80x94CH2NHC(xe2x95x90O)CH3).
It may be convenient or desirable to prepare, purify, and/or handle the active compound in the form of a prodrug. The term xe2x80x9cprodrugxe2x80x9d, as used herein, pertains to a compound which, when metabolised (e.g. in vivo), yields the desired active compound. Typically, the prodrug is inactive, or less active than the active compound, but may provide advantageous handling, administration, or metabolic properties.
For example, some prodrugs are esters of the active compound (e.g. a physiologically acceptable metabolically labile ester). During metabolism, the ester group (xe2x80x94C(xe2x95x90O)OR) is cleaved to yield the active drug. Such esters may be formed by esterification, for example, of any of the carboxylic acid groups (xe2x80x94C(xe2x95x90O)OH) in the parent compound, with, where appropriate, prior protection of any other reactive groups present in the parent compound, followed by deprotection if required. Examples of such metabolically labile esters include those wherein R is C1-7alkyl (e.g. -Me, -Et); C1-7 aminoalkyl (e.g. aminoethyl; 2-(N,N-diethylamino)ethyl; 2-(4-morpholino)ethyl); and acyloxy-C1-7alkyl (e.g. acyloxymethyl; acyloxyethyl; e.g. pivaloyloxymethyl; acetoxymethyl; 1-acetoxyethyl; 1-(1-methoxy-1-methyl)ethyl-carbonxyloxyethyl; 1-(benzoyloxy)ethyl; isopropoxy-carbonyloxymethyl; 1-isopropoxy-carbonyloxyethyl; cyclohexyl-carbonyloxymethyl; 1-cyclohexyl-carbonyloxyethyl; cyclohexyloxy-carbonyloxymethyl; 1-cyclohexyloxy-carbonyloxyethyl; (4-tetrahydropyranyloxy) carbonyloxymethyl; 1-(4-tetrahydropyranyloxy) carbonyloxyethyl; (4-tetrahydropyranyl)carbonyloxymethyl; and 1-(4-tetrahydropyranyl)carbonyloxyethyl). Further suitable prodrug forms include phosphonate and glycolate salts.
Also, some prodrugs are activated enzymatically to yield the active compound, or a compound which, upon further chemical reaction, yields the active compound. For example, the prodrug may be a sugar derivative or other glycoside conjugate, or may be an amino acid ester derivative.
Acronyms
For convenience, many chemical moieties are represented using well known abbreviations, including but not limited to, methyl (Me), ethyl (Et), n-propyl (nPr), iso-propyl (iPr), n-butyl (nBu), tert-butyl (tBu), n-hexyl (nHex), cyclohexyl (cHex), phenyl (Ph), biphenyl (biPh), benzyl (Bn), naphthyl (naph), methoxy (MeO), ethoxy (EtO), benzoyl (Bz), and acetyl (Ac).
For convenience, many chemical compounds are represented using well known abbreviations, including but not limited to, methanol (MeOH), ethanol (EtOH), iso-propanol (i-PrOH), methyl ethyl ketone (MEK), ether or diethyl ether (Et2O), acetic acid (AcOH), dichloromethane (methylene chloride, DCM), trifluoroacetic acid (TFA), dimethylformamide (DMF), tetrahydrofuran (THF), and dimethylsulfoxide (DMSO).
Synthesis
Compounds as described in the first aspect can be synthesised by a number of methods, examples of some of which are given below.
The following papers provide routes to compounds within the general class illustrated (where Arxe2x95x90C5-20 aryl) and these papers are herein incorporated by reference.
I. W. Elliott and Y. Takekoshi, J. Heterocyclic Chem., 1976, 13, 597. 
K. Masayasu, I. Waki, Y. Deguchi, K. Amemiya and T. Maeda, Chem. Pharm. Bull., 1983, 31(4), 1277. 
The formed aromatic ring (represented by -A-B-) is usually derivatised before the main synthesis steps, and starting materials with the desired structure and substituent pattern are either commercially available or readily synthesised.
The main synthesis steps may lead to compounds where RN is H. The possible substituents at this position can be added by the use of an appropriate electrophile with suitable reaction conditions.
Further derivatisation of the groups on RC1 and RC2 can be carried out using conventional methods.
Synthesis of 3-Substituted Isoquinolinones
Compounds of the present invention in which RC1 is H and RC2, RN, A and B are as defined in the first aspect and the bond joining positions 3 and 4 is a double bond, may be synthesised by reaction of a compound of Formula 1: 
in which RC2, A and B are as previously defined, with a compound of formula RNNH2, in which RN is as previously defined, at a temperature in the range of 100-200xc2x0 C., optionally in a sealed vessel so as to generate high pressure, optionally in the presence of a solvent, for example methanol.
Compounds of Formula 1 may be synthesised by reaction of a compound of Formula 2: 
in which A and B are as defined above, with a compound of formula RC2COX, in which RC2 is as previously defined and X is a leaving group, for example a halogen such as chlorine, at a temperature in the range of 100-250xc2x0 C., optionally in the presence of a solvent, for example xylene.
Compounds of Formula 2 are commercially available or may be readily prepared by known methods.
Synthesis of 4-Substituted Isoquinolinones
Compounds of the present invention in which RC1 is an arylalkyl group of formula RLCHR1xe2x80x94 in which RL and R1 are as defined in the first aspect, RC2 and RN are H and A and B are as defined in the first aspect and the bond joining positions 3 and 4 is a double bond, may be synthesised by reaction of a compound of Formula 3: 
in which A, B, RL and R1 are as previously defined, with a dehydrating agent, for example toluene-4-sulphonic acid, at a temperature in the range of 20-150xc2x0 C., optionally in the presence of a solvent, for example toluene.
Compounds of Formula 3 may be synthesised by reaction of a compound of Formula 4: 
in which A, B, RL and R1 are as previously defined with a reducing agent, for example a source of hydride such as sodium borohydride, in a solvent, for example methanol, at a temperature in the range of xe2x88x9220xc2x0 C. to the boiling point of the chosen solvent.
Compounds of Formula 4 may be synthesised by reduction of a compound of Formula 5: 
in which A, B, RL and R1 are as previously defined with a reducing agent, for example hydrogen, in the presence of an appropriate catalyst, for example palladium-on-carbon, in the presence of a solvent, for example methanol, at a temperature in the range of 20xc2x0 C. to the boiling point of the chosen solvent, optionally under increased pressure.
Compounds of Formula 3 may also be synthesised directly from Compounds of Formula 5 by reaction with a reducing agent, for example a source of hydride such as sodium borohydride, in a solvent, for example methanol, at a temperature in the range of xe2x88x9220xc2x0 C. to the boiling point of the chosen solvent.
Compounds of Formula 5 may be synthesised by reaction of a compound of Formula 6: 
in which A and B are as previously defined, with a carbonyl compound of Formula RLCOR1 in which RL and R1 are as previously defined, in the presence of a base, for example piperidine, optionally in the presence of a solvent, for example acetic acid, at a temperature in the range of 20xc2x0 C. to the boiling point of the chosen solvent.
Compounds of Formula 6 may be synthesised by reaction of a compound of Formula 2 with urea at a temperature in the range of 150-190xc2x0 C.
Synthesis of 3- or 4-Substituted 3,4-dihydroisoquinolones
Compounds of the present invention in which the bond joining positions 3 and 4 is a single bond (i.e. Compounds of Formula 7): 
in which RC1, RC2, RN, A and B are as defined in the first aspect may be synthesised by reduction of Compounds of the present invention in which the bond joining positions 3 and 4 is a double bond (i.e. Compounds of Formula 8): 
in which RC1, RC2, RN, A and B are as defined in the first aspect with a reducing agent, for example hydrogen or ammonium formate, in the presence of an appropriate catalyst, for example palladium-on-carbon or Raney Nickel, in the presence of a solvent, for example ethanol or acetic acid, at a temperature in the range of 20xc2x0 C. to the boiling point of the chosen solvent, optionally under increased pressure.
Use
The present invention provides active compounds, specifically, active in inhibiting the activity of PARP.
The term xe2x80x98activexe2x80x99, as used herein, pertains to compounds which are capable of inhibiting PARP activity, and specifically includes both compounds with intrinsic activity (drugs) as well as prodrugs of such compounds, which prodrugs may themselves exhibit little or no intrinsic activity.
One assay which may conveniently be used in order to assess the PARP inhibition offered by a particular compound is described in the examples below.
The present invention further provides a method of inhibiting the activity of PARP in a cell, comprising contacting said cell with an effective amount of an active compound, preferably in the form of a pharmaceutically acceptable composition. Such a method may be practised in vitro or in vivo.
For example, a sample of cells may be grown in vitro and an active compound brought into contact with said cells, and the effect of the compound on those cells observed. As examples of xe2x80x9ceffectxe2x80x9d the amount of DNA repair effected in a certain time may be determined. Where the active compound is found to exert an influence on the cells, this may be used as a prognostic or diagnostic marker of the efficacy of the compound in methods of treating a patient carrying cells of the same cellular type.
The term xe2x80x9ctreatmentxe2x80x9d as used herein in the context of treating a condition pertains generally to treatment and therapy, whether of a human or an animal (e.g. in veterinary applications), in which some desired therapeutic effect is achieved, for example, the inhibition of the progress of the condition, and includes a reduction in the rate of progress, a halt in the rate of progress, amelioration of the condition, and cure of the condition. Treatment as a prophylactic measure (i.e. prophylaxis) is also included.
The term xe2x80x9cadjunctxe2x80x9d as used herein relates to the use of active compounds in conjunction with known therapeutic means. Such means include cytotoxic regimes of drugs and/or ionising radiation as used in the treatment of different cancer types.
The term xe2x80x9ctherapeutically-effective amountxe2x80x9d, as used herein, pertains to that amount of an active compound, or a material, composition or dosage from comprising an active compound, which is effective for producing some desired therapeutic effect, commensurate with a reasonable benefit/risk ratio.
Active compounds may also be used as cell culture additives to inhibit PARP, for example, in order to radio-sensitize cells to known chemo or ionising radiation treatments in vitro.
Active compounds may also be used as part of an in vitro assay, for example, in order to determine whether a candidate host is likely to benefit from treatment with the compound in question.
Administration
The active compound or pharmaceutical composition comprising the active compound may be administered to a subject by any convenient route of administration, whether systemically/peripherally or at the site of desired action, including but not limited to, oral (e.g. by ingestion); topical (including e.g. transdermal, intranasal, ocular, buccal, and sublingual); pulmonary (e.g. by inhalation or insufflation therapy using, e.g. an aerosol, e.g. through mouth or nose); rectal; vaginal; parenteral, for example, by injection, including subcutaneous, intradermal, intramuscular, intravenous, intraarterial, intracardiac, intrathecal, intraspinal, intracapsular, subcapsular, intraorbital, intraperitoneal, intratracheal, subcuticular, intraarticular, subarachnoid, and intrasternal; by implant of a depot, for example, subcutaneously or intramuscularly.
The subject may be a eukaryote, an animal, a vertebrate animal, a mammal, a rodent (e.g. a guinea pig, a hamster, a rat, a mouse), murine (e.g. a mouse), canine (e.g. a dog), feline (e.g. a cat), equine (e.g. a horse), a primate, simian (e.g. a monkey or ape), a monkey (e.g. marmoset, baboon), an ape (e.g. gorilla, chimpanzee, orangutang, gibbon), or a human.
Formulations
While it is possible for the active compound to be administered alone, it is preferable to present it as a pharmaceutical composition (e.g. formulation) comprising at least one active compound, as defined above, together with one or more pharmaceutically acceptable carriers, adjuvants, excipients, diluents, fillers, buffers, stabilisers, preservatives, lubricants, or other materials well known to those skilled in the art and optionally other therapeutic or prophylactic agents.
Thus, the present invention further provides pharmaceutical compositions, as defined above, and methods of making a pharmaceutical composition comprising admixing at least one active compound, as defined above, together with one or more pharmaceutically acceptable carriers, excipients, buffers, adjuvants, stabilisers, or other materials, as described herein.
The term xe2x80x9cpharmaceutically acceptablexe2x80x9d as used herein pertains to compounds, materials, compositions, and/or dosage forms which are, within the scope of sound medical judgement, suitable for use in contact with the tissues of a subject (e.g. human) without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit/risk ratio. Each carrier, excipient, etc. must also be xe2x80x9cacceptablexe2x80x9d in the sense of being compatible with the other ingredients of the formulation.
Suitable carriers, excipients, etc. can be found in standard pharmaceutical texts, for example, Remington""s Pharmaceutical Sciences, 18th edition, Mack Publishing Company, Easton, Pa., 1990.
The formulations may conveniently be presented in unit dosage form and may be prepared by any methods well known in the art of pharmacy. Such methods include the step of bringing into association the active compound with the carrier which constitutes one or more accessory ingredients. In general, the formulations are prepared by uniformly and intimately bringing into association the active compound with liquid carriers or finely divided solid carriers or both, and then if necessary shaping the product.
Formulations may be in the form of liquids, solutions, suspensions, emulsions, elixirs, syrups, tablets, losenges, granules, powders, capsules, cachets, pills, ampoules, suppositories, pessaries, ointments, gels, pastes, creams, sprays, mists, foams, lotions, oils, boluses, electuaries, or aerosols.
Formulations suitable for oral administration (e.g. by ingestion) may be presented as discrete units such as capsules, cachets or tablets, each containing a predetermined amount of the active compound; as a powder or granules; as a solution or suspension in an aqueous or non-aqueous liquid; or as an oil-in-water liquid emulsion or a water-in-oil liquid emulsion; as a bolus; as an electuary; or as a paste.
A tablet may be made by conventional means, e.g. compression or molding, optionally with one or more accessory ingredients. Compressed tablets may be prepared by compressing in a suitable machine the active compound in a free-flowing form such as a powder or granules, optionally mixed with one or more binders (e.g. povidone, gelatin, acacia, sorbitol, tragacanth, hydroxypropylmethyl cellulose); fillers or diluents (e.g. lactose, microcrystalline cellulose, calcium hydrogen phosphate); lubricants (e.g. magnesium stearate, talc, silica); disintegrants (e.g. sodium starch glycolate, cross-linked povidone, cross-linked sodium carboxymethyl cellulose); surface-active or dispersing or wetting agents (e.g. sodium lauryl sulfate); and preservatives (e.g. methyl p-hydroxybenzoate, propyl p-hydroxybenzoate, sorbic acid). Molded tablets may be made by molding in a suitable machine a mixture of the powdered compound moistened with an inert liquid diluent. The tablets may optionally be coated or scored and may be formulated so as to provide slow or controlled release of the active compound therein using, for example, hydroxypropylmethyl cellulose in varying proportions to provide the desired release profile. Tablets may optionally be provided with an enteric coating, to provide release in parts of the gut other than the stomach.
Formulations suitable for topical administration (e.g. transdermal, intranasal, ocular, buccal, and sublingual) may be formulated as an ointment, cream, suspension, lotion, powder, solution, past, gel, spray, aerosol, or oil. Alternatively, a formulation may comprise a patch or a dressing such as a bandage or adhesive plaster impregnated with active compounds and optionally one or more excipients or diluents.
Formulations suitable for topical administration in the mouth include losenges comprising the active compound in a flavored basis, usually sucrose and acacia or tragacanth; pastilles comprising the active compound in an inert basis such as gelatin and glycerin, or sucrose and acacia; and mouthwashes comprising the active compound in a suitable liquid carrier.
Formulations suitable for topical administration to the eye also include eye drops wherein the active compound is dissolved or suspended in a suitable carrier, especially an aqueous solvent for the active compound.
Formulations suitable for nasal administration, wherein the carrier is a solid, include a coarse powder having a particle size, for example, in the range of about 20 to about 500 microns which is administered in the manner in which snuff is taken, i.e., by rapid inhalation through the nasal passage from a container of the powder held close up to the nose. Suitable formulations wherein the carrier is a liquid for administration as, for example, nasal spray, nasal drops, or by aerosol administration by nebuliser, include aqueous or oily solutions of the active compound.
Formulations suitable for administration by inhalation include those presented as an aerosol spray from a pressurised pack, with the use of a suitable propellant, such as dichlorodifluoromethane, trichlorofluoromethane, dichoro-tetrafluoroethane, carbon dioxide, or other suitable gases.
Formulations suitable for topical administration via the skin include ointments, creams, and emulsions. When formulated in an ointment, the active compound may optionally be employed with either a paraffinic or a water-miscible ointment base. Alternatively, the active compounds may be formulated in a cream with an oil-in-water cream base. If desired, the aqueous phase of the cream base may include, for example, at least about 30% w/w of a polyhydric alcohol, i.e. an alcohol having two or more hydroxyl groups such as propylene glycol, butane-1,3-diol, mannitol, sorbitol, glycerol and polyethylene glycol and mixtures thereof. The topical formulations may desirably include a compound which enhances absorption or penetration of the active compound through the skin or other affected areas. Examples of such dermal penetration enhancers include dimethylsulfoxide and related analogues.
When formulated as a topical emulsion, the oily phase may optionally comprise merely an emulsifier (otherwise known as an emulgent), or it may comprises a mixture of at least one emulsifier with a fat or an oil or with both a fat and an oil. Preferably, a hydrophilic emulsifier is included together with a lipophilic emulsifier which acts as a stabiliser. It is also preferred to include both an oil and a fat. Together, the emulsifier(s) with or without stabiliser(s) make up the so-called emulsifying wax, and the wax together with the oil and/or fat make up the so-called emulsifying ointment base which forms the oily dispersed phase of the cream formulations.
Suitable emulgents and emulsion stabilisers include Tween 60, Span 80, cetostearyl alcohol, myristyl alcohol, glyceryl monostearate and sodium lauryl sulphate. The choice of suitable oils or fats for the formulation is based on achieving the desired cosmetic properties, since the solubility of the active compound in most oils likely to be used in pharmaceutical emulsion formulations may be very low. Thus the cream should preferably be a non-greasy, non-staining and washable product with suitable consistency to avoid leakage from tubes or other containers. Straight or branched chain, mono- or dibasic alkyl esters such as di-isoadipate, isocetyl stearate, propylene glycol diester of coconut fatty acids, isopropyl myristate, decyl oleate, isopropyl palmitate, butyl stearate, 2-ethylhexyl palmitate or a blend of branched chain esters known as Crodamol CAP may be used, the last three being preferred esters. These may be used alone or in combination depending on the properties required. Alternatively, high melting point lipids such as white soft paraffin and/or liquid paraffin or other mineral oils can be used.
Formulations suitable for rectal administration may be presented as a suppository with a suitable base comprising, for example, cocoa butter or a salicylate.
Formulations suitable for vaginal administration may be presented as pessaries, tampons, creams, gels, pastes, foams or spray formulations containing in addition to the active compound, such carriers as are known in the art to be appropriate.
Formulations suitable for parenteral administration (e.g. by injection, including cutaneous, subcutaneous, intramuscular, intravenous and intradermal), include aqueous and non-aqueous isotonic, pyrogen-free, sterile injection solutions which may contain anti-oxidants, buffers, preservatives, stabilisers, bacteriostats, and solutes which render the formulation isotonic with the blood of the intended recipient; and aqueous and non-aqueous sterile suspensions which may include suspending agents and thickening agents, and liposomes or other microparticulate systems which are designed to target the compound to blood components or one or more organs. Examples of suitable isotonic vehicles for use in such formulations include Sodium Chloride Injection, Ringer""s Solution, or Lactated Ringer""s Injection. Typically, the concentration of the active compound in the solution is from about 1 ng/ml to about 10 xcexcg/ml, for example from about 10 ng/ml to about 1 xcexcg/ml. The formulations may be presented in unit-dose or multi-dose sealed containers, for example, ampoules and vials, and may be stored in a freeze-dried (lyophilised) condition requiring only the addition of the sterile liquid carrier, for example water for injections, immediately prior to use. Extemporaneous injection solutions and suspensions may be prepared from sterile powders, granules, and tablets. Formulations may be in the form of liposomes or other microparticulate systems which are designed to target the active compound to blood components or one or more organs.
Dosage
It will be appreciated that appropriate dosages of the active compounds, and compositions comprising the active compounds, can vary from patient to patient. Determining the optimal dosage will generally involve the balancing of the level of therapeutic benefit against any risk or deleterious side effects of the treatments of the present invention. The selected dosage level will depend on a variety of factors including, but not limited to, the activity of the particular compound, the route of administration, the time of administration, the rate of excretion of the compound, the duration of the treatment, other drugs, compounds, and/or materials used in combination, and the age, sex, weight, condition, general health, and prior medical history of the patient. The amount of compound and route of administration will ultimately be at the discretion of the physician, although generally the dosage will be to achieve local concentrations at the site of action which achieve the desired effect without causing substantial harmful or deleterious side-effects.
Administration in vivo can be effected in one dose, continuously or intermittently (e.g. in divided doses at appropriate intervals) throughout the course of treatment. Methods of determining the most effective means and dosage of administration are well known to those of skill in the art and will vary with the formulation used for therapy, the purpose of the therapy, the target cell being treated, and the subject being treated. Single or multiple administrations can be carried out with the dose level and pattern being selected by the treating physician.
In general, a suitable dose of the active compound is in the range of about 100 xcexcg to about 250 mg per kilogram body weight of the subject per day. Where the active compound is a salt, an ester, prodrug, or the like, the amount administered is calculated on the basis of the parent compound and so the actual weight to be used is increased proportionately.